Interpretive Summary: Genomic projects allow a deep understanding of agricultural organisms, including the honey bee, by presenting the entire genetic blueprint with which these organisms must grow and reproduce. In the case of the honey bee, recent genomic advances involve pollination and other behaviors, disease resistance, and the production of healthy queens and workers. These advances are now in use as diagnostic tools, and soon will be used in breeding programs aimed at keeping honey bees as a key pollinator of agricultural crops. One of the most unexpected recent discoveries from genome projects is the importance of tiny sections of RNA that play a huge role in regulating genetic information. Our description here of such ‘microRNA’s’ in the honey bee is aimed at understanding their impacts on honey bee biology. This analysis should tie to together honey bee traits involving development, behavior, and disease resistance, providing researchers with a new tool for understanding and enhancing these traits in an important agricultural species.

Technical Abstract:
Noncoding microRNAs (miRNAs) are key regulators of gene expression in eukaryotes. Insect miRNAs help regulate the levels of proteins involved with development, metabolism, and other life history traits. The recently sequenced honeybee genome provides an opportunity to detect novel miRNAs in both this species and others, and begin to infer the roles of miRNAs in honeybee development. Three independent computational surveys of the assembled honeybee genome identified a total of 65 non-redundant candidate miRNAs, several of which appear to have previously unrecognized orthologs in the Drosophila genome. A subset of these candidate miRNAs were detected as mature transcripts. Among those canonical miRNAs tested in Apis mellifera, miR-1, miR-2, miR-9a, miR-9b, miR-10, miR-71, miR-310 and bantam exhibited evidence of expression in honeybee. We also developed evidence of transcription in honeybee for several novel miRNAs. Interestingly, the transcript abundance for many of these mature miRNAs displayed caste or age-related differences.